Identification and genomic characterisation of known and novel highly divergent sapoviruses in frugivorous and insectivorous bats in Nigeria

Abstract

Sapovirus (SaV) infections have been linked with moderate-to-severe acute gastroenteritis (AGE) in animals and humans and represent a significant risk to public health. SaVs from animals including pigs, chimpanzees, and rodents have been reported to be closely related with human SaVs, indicating the possibility of cross-species transmission. Divergent SaVs have been reported in various bat species across various continents including Asia, Europe, Oceania and Africa. However, little is known about the evolutionary history of SaVs across various bat species and their zoonotic potential. In this report, we describe the findings of a surveillance study across various bat species in Nigeria. Samples were pooled and subjected to metagenomics sequencing and analyses. Nine of 57 sample pools (containing 223 rectal swabs from five bat species) had SaV reads from which we assembled a total of four complete and three near-complete (having complete coding sequences) genomes. The bat SaV (BtSaV) strains from this study formed five distinct lineages of which four represented novel genogroups. BtSaV lineages clustered mainly according to bat families, which might suggest a likely virus-host-specific evolution. The BtSaV VP1 capsid protein structure prediction confirmed three main domains (S, P1, and P2) as reported for Human SaV (HuSaV). We found that the P2 subdomain of the VP1 protein contains a degree of homology to known immunoreactive epitopes suggesting these conserved regions may be valuable for diagnostics or medical countermeasure development. This study expands our understanding of reservoir hosts, provides information on the genetic diversity and continuous evolution of SaVs in bats.